Primer testing

[boonewsm]

I did some primer testing yesterday and I thought I'd share the results

Desert Tech SRSA1
Factory 260 barrel +- 2000 rounds down it
Lapua brass stainless cleaned, annealed, chamfered and deburred
Neck sized
H4350 @ 42.6 grains
Berger 140 Hybrids
AAC MK13 suppressor
Magneto v2 chrono

Temp was 90 degrees and the DA was 3520

Primers tested were Federal 210M and CCI BR2

Br2

Test 1 5 shots 1 minute between shots
2788. 2791. 2791. 2829. 2797.
SD 16. Es 41

Test 2 5 shots in 1 minute
2773 2815 2799 2834 2808
SD 22. Es 61

Fed 210m
Test 1. 5 shots 1 minute between shots
2813 2815 2826 2821 2815
SD 5. Es 13

Test 2 5 shots in under 1 minute.
2829 2845 2839 2823 2816
SD 11. Es 29.

 

[shoot4fun]

Interesting comparison. Since Federal and CCI are basically the same company I wonder why the mixes seem so different among their match primers?

 

[308sako]

Chiller once asked me to do a primer test or comparison. The results:

Note the velocities and the deviations are nearly identical for such a small sample, but the dispersion was like two different rifles being fired. Range to target was 400 yards. .308 Winchester, 175 SMK's in a Rock Creek barreled M700. Wolf on the left, Federal on the right.

 

[918v]

What are you testing for?

210's are going to behave differently than BR-2's. In another load you might see the reverse.

 

[boonewsm]

I was trying to get my es/sd down. All I had when I worked up this load was wlr and since things have slowed down I found some 210s and br2 to try out. My sd with the wlr were 15-20

 

[zipollini]

Did a search and found this

Primer Testing Reference

 

[lash]

Did a search and found this

Primer Testing Reference

Nice! That's an interesting test.

 

[308sako]

Neck tension and uniformity of all factors weigh in to low SD's. Powder choice relative to case capacity and shape also can make a major difference. Lot to lot variation can reverse your results. You are playing on the devils court.

 

[boonewsm]

Neck tension and uniformity of all factors weigh in to low SD's. Powder choice relative to case capacity and shape also can make a major difference. Lot to lot variation can reverse your results. You are playing on the devils court.

I try to do everything as good as I can. Every load is trickled up to the right weight on a gempro250. I buy primers,powder, bullets in bulk. I have 32#s of h4350 of the same powder lot. I understand there are a lot more things to making that perfect load than just changing primers. I made a 3rd hit at a mile with the 260 and the load I've been using so its not to bad just thought there might be room for improvement.


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[.Mark.]

Would you guys consider outside neck turning?


- Mark